Backyard Gardener (Photo Illustration/MetroCreative)
Hello farmers and gardeners of the Mid-Ohio Valley, With the beautiful sunshine and mild temperatures we have had this week, I wanted to talk to you about summer lawn care.
Though summer doesn't officially start until June 21, the weather can change from week to week. Now is the perfect time to start planning for summer's hot, dry weather. Summer is on track to arrive next week with temperatures expected to rise into the upper 90s. This combination of heat and dryness can take its toll on your lawn. Now is the time to take proactive steps to help your lawn survive the onslaught of summer.
First, let's look at your mowing height. We recommend setting your mower deck at 3-4 inches. This will keep weeds covered, reduce water loss through evaporation, and encourage stronger, drought-resistant root systems. You'll be guaranteed a healthier, more attractive lawn.
Elevated mowing reduces the amount of water used by plants, keeping the grass greener longer. Increasing the height of the mowing deck is extremely beneficial for cool season grasses such as bluegrass and tall fescue during very hot, dry periods in the summer.
Longer leaf blades shade the soil, reducing soil temperature and water loss. These conditions promote root growth, which is essential for increased summer hardiness.
In addition to the correct cutting height, make sure your lawnmower blades are sharp. Dull blades will tear grass blades, increasing water loss and causing excessive browning of grass blades. Dull blades also leave jagged cuts that make plants more susceptible to disease.
A neatly cut lawn conserves water, reducing the need for irrigation. Dull blades often give the grass a chalky appearance. Sharp mower blades make cutting easier and reduce engine resistance, resulting in faster mowing and a longer mower life. Dull mower blades also increase the likelihood of a hard cut and uneven grass length.
Mower blades should be sharpened or replaced regularly as part of the overall maintenance of your lawn and mower. It's a good idea to keep a few spare blades on hand – you can sharpen them yourself or take them to your local shop.
We recommend leaving grass clippings on the lawn to help keep your lawn healthy. Grass clippings break down quickly and encourage the growth of beneficial microorganisms and earthworms. The nutrients in the grass clippings are recycled back into the lawn, promoting healthy grass growth. Leaving grass clippings on the lawn saves both manpower and fuel energy by eliminating the need to bag and transport them.
Grass clippings contain nitrogen and other nutrients. Returning grass clippings to your lawn recycles the nutrients in a slow-release organic form, promoting steady grass growth. Returning grass clippings to your lawn reduces the amount of nitrogen fertilizer your lawn needs.
The belief that leaving grass clippings on your lawn causes thatch is a misconception – regular core-tilling (aeration) is the best way to prevent thatch.
Core tilling, or aeration, is another important method of lawn maintenance. It opens air passages and relieves soil compaction. It can be done as often as needed as long as the root system is actively growing. For homeowners, an economical way to do this is to borrow an aeration device from a neighbor.
Soil compaction can be a problem in clay soils. This is alleviated by aeration. Compacted soil means there is limited subsurface soil space through which water, nutrients, and air can move freely. To grow a healthy, thick lawn on top of the soil, you need a healthy, well-developed root system below the soil.
Dry summer weather is not ideal for fertilizing a cool-season lawn. Do not over-apply nitrogen fertilizer in hot, dry weather. The lawn will respond by over-growing when it should be going dormant. Drought stress develops more quickly in lawns with poor soil condition. Soil compaction, clay accumulation, low pH, and general poor conditions for root growth are much more pronounced under stressful conditions such as drought.
The best time to fertilize bluegrass and tall fescue is in the fall, in September and November. In fact, spring fertilization should be avoided unless the lawn is adequately watered during the summer. Spring fertilization provides little benefit to the lawn other than making it greener and more lush. This lush growth increases the need for mowing.
With a normal summer watering schedule, applying a slow-release fertilizer in mid-May is fine.
Here in the Mid-Ohio Valley, dry periods in the summer are almost inevitable. During dry periods, many lawns show the early symptoms of drought stress. As the grass loses moisture, it loses firmness in its leaves and begins to wilt. The reason footprints are left after walking on the grass is because the grass stays flat after being stepped on, rather than “bounce back.”
The most obvious symptom of drought stress is when the grass blades turn a crispy tan or brown as they go dormant, helping the plant conserve water to survive the drought. Drought stress is most evident on slopes in grasses with poor soil or shallow topsoil.
Once your cool-season grass has stopped active growth, lost color and gone dormant, it's best to leave it that way rather than killing it with heavy watering.
Your lawn will become green again. Breaking dormancy actually depletes the root reserves within the plant. If conditions remain dry and temperatures are high, the plant will be less likely to replenish those reserves. In a normal summer, your lawn will go dormant and resume active growth when conditions improve. The downside to dormancy is the appearance of your lawn and the risk of problems developing with an inactive lawn, such as opportunistic weed germination.
Many homeowners want to know how much water their lawn needs to stay vibrant. To keep your lawn green during hot, dry periods, you need to give it at least an inch of water every week. Not only is this expensive, but it can also use a significant amount of water during extended dry periods.
The best way to care for your lawn is to follow the recommended methods determined in university research. If you have any questions, please contact the Wood County WVU Extension Office at 304-424-1960 or email me at jj.barrett@mail.wvu.edu. We wish you success in your gardening endeavors!
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Question of the week: What is insecticidal soap and how do you use it?
Insecticidal soap is applied foliarly (sprayed on the leaves of plants) and is effective against a wide range of plant pests when the soap spray comes into contact with the pests.
Most commercial insecticidal soaps are made of potassium salts of fatty acids, which destroy the structure and permeability of insect cell membranes, killing them. Insecticidal soaps are most effective against soft-bodied insects such as aphids, adelgids, lacebugs, leafhoppers, mealybugs, thrips, sawfly larvae, spider mites, and whiteflies.
It has no effect on pests when left on plant surfaces and is not toxic to pollinators after the spray has dried. It can be safely used at any time to control pests on plants that do not attract pollinators, except for plants that do attract pollinators, which should be sprayed at dawn or dusk when pollinators are not present.
In general, concentrations of insecticidal soap above 3% can cause some damage to leaves and flowers, and concentrations as low as 1.5% can damage sensitive plants. Read the product label for a list of sensitive plants and avoid spraying such plants. If you are unsure of a plant's susceptibility, spray a few leaves or flowers first and wait at least 3 days to observe for symptoms of spray damage such as yellow, black, or brown spots, brown (necrotic) edges on leaf or petal tips, scorching, or discoloration.
Garden plants known to be sensitive to insecticidal soaps include horse chestnut, mountain ash, Japanese maple, sweetgum, jade, lantana, gardenia, bloodheart, sweet pea, onion, and some cultivars of azalea, begonia, chrysanthemum, fuchsia, and impatiens.
It's best to buy a commercial product formulated for plants rather than making your own spray out of dish soap or other household cleaners, as homemade versions can be harmful to plants – most such products are detergents, not real soaps, which can damage plants.
They are specially formulated and labeled for use as insecticides. Many insecticidal soap products are listed by the Organic Materials Review Institute (OMRI) at www.omri.org.
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